Date post: | 25-Dec-2015 |
Category: |
Documents |
Upload: | alisha-nash |
View: | 234 times |
Download: | 2 times |
Copyright © 2001-2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing (Poka-Yoke)
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 2
The Breakthrough Strategy®
And The Control Phase
1. Select Output Characteristic
2. Define Performance Standards
3. Validate Measurement System
4. Establish Baseline Process Capability
5. Define Performance Objectives
6. Identify Variation Sources
7. Screen Potential Causes
8. Discover Variable Relationships
9. Establish Operating Tolerances – Implement Improvements
10. Validate Measurement System
11. Determine Final Process Capability
12. Implement Process Controls
• Implement controls on the key Xs
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 3
Module Objectives
By the end of this module, the participant will be able to:
• Understand the concept of Mistake Proofing as a control method
• Apply Poka-Yoke methods as a control on identified key xs- Reduce and/or eliminate process errors from occurring- Reduce and/or eliminate process defects from occurring
• Understand “red flag” conditions
1 2 3 4 5 6 7 8 9 10 11 12D M A CI
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 4
Why Is Mistake Proofing Important?
• Improved quality and customer satisfaction
• Prevents error occurrence
• Prevents defect occurrence
• If defects occur, ensures effective action
• Little or no formal training
• Cost effective
• Easy to implement
Mistake Proofing is one of the most cost effective and reliable controls that can be used to assure that our key Xs remain at our optimum
project defined settings. It can also be used directly on the Y.
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 5
What Is Mistake Proofing (Poka-Yoke)?
• Japanese phrase: - Yokeru (to avoid), Poka (errors)
• A strategy for preventing errors in processes
• Makes it impossible for defects to pass unnoticed
• Corrects problems as soon as they are detected
• Technique detects defects
• Prevents defects from moving into next area
• Developed by Dr. Shigeo Shingo to achieve zero defects
Mistake Proof devices cannot be implemented until the key Xs needing to be controlled have been identified and settings
established (Establish Operating Tolerances, Step 11).
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 6
What’s The Secret Of Poka-Yoke?
“What’s the secret? It’s a mystery to me – Our plant is as sophisticated as you can get, yet with all this innovation at our disposal we still make defects. I can’t believe all those statistics about parts per million and zero defects coming from Japan. There must be a gimmick. With all the variability of parts coming from hundreds of vendors and going through fifty different processes with a hundred machines, it is impossible not to produce some defects. So what’s the trick? Where is thehidden weapon?”
Norman BodekPublisherPoka-Yoke, Improving Product Quality by Preventing Defects
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 7
The Secret Of Dr. Shigeo Shingo
“It is not one Poka-Yoke device, but the application of hundreds of these very simple fail-safeing mechanisms that, day after day, has brought the quality miracle to industries around the world.
Each one is relatively simple – Something you easily could do on your own. But it is the totality, the hundreds of devices, that is almost frightening to behold.”
Dr. Shigeo Shingo
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 8
• Guide pins of different sizes
• Optical magnification
• Different colored tags for pressure ranges
• Look up tables for data base entry
• Spell check
• Limit switches
• Error alarms
• Counters
• Checklists
• Asymmetric parts
• Build error checking into control logic
• Exact part count
Common Examples Of Mistake Proofing
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 9
Xdthx th xth
yj fyjdtyj______
dxrt____ rtjh
dxrtj__
d tsthy sety
drtudrtud
__________
Mistake Proofing Business Processes
• Mistake Proofing is the primary means of control for many business processes
- Check digits- Pull down menus- Check sheets- Required fields
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 10
Basics Of Mistake Proofing
Effective Mistake Proofing requires two basic concepts
• A focus on controlling the factors which cause errors – Not fixing the resulting defective output (Sigma Lean Concept)
• Inspection which is effective and tireless- This IS NOT traditional 100% inspection by inspectors- This IS a mechanical or process improvement that automatically
performs the inspection with little to no human interaction
Can not do it wrong. Can only do it one way.
If wrong, detected 100%.Can not be passed into next area.
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 11
What Does Mistake Proofing Do?
3. Output1. Input 2. Process
Ideal:
1. This process will not accept any bad parts
2. This process will not make any bad parts
3. This process will not pass on any bad parts
• The ideal process is mistake proofed at three stages:- Input - Process - Output
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 12
Error Proofing In Action
• What are the error opportunities in these everyday items?
• How have they been error proofed?
• How could they be further error proofed?
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 13
Error Proofing In Action
• What are the error opportunities in these everyday items?
• How have they been error proofed?
• How could they be further error proofed?
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 14
Class Exercise
Round Robin: Let’s go around the class twice.
1. The first time each participant will list a Mistake Proofing idea from one of the following:
• Home (e.g., auto shut off on flat iron)
• Auto (e.g., car won’t start unless transmission is in park/neutral)
• Sport/Recreation (e.g., dead man’s lanyard on personal watercraft)
• Amusement Parks (e.g., sensors on roller coaster tracks)
• Work/Commerce (e.g., pull down menus on forms)
• Etc.
2. The second time around, you will be asked to identify a possible Mistake Proofing for some potential vital X from your project
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 15
My New Spell Checker
Eye halve a spelling chequer It came with my pea sea
It plainly marques four my revue Miss steaks eye kin knot sea.
Eye strike a key and type a word And weight four it two say
Weather eye am wrong oar write It shows me strait a weigh.
As soon as a mist ache is maid It nose bee fore two long
And eye can put the error rite Its rare lea ever wrong.
Eye have run this poem threw it I am shore your pleased two no
Its letter perfect awl the weigh My chequer tolled me sew.
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 16
Evolution Of Defectives And Application Of Mistake Proofing
ERRORS
DEFECTS
DEFECTIVES
The Value of Mistake
Proofing
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 17
Ten Common Errors That Lead To Defects(Things That Can Cause Your Key X To Go Astray)
Errors are the cause of defects
1. Processing errors
2. Error in setting up job
3. Processing omissions
4. Assembly omissions (missing parts)
5. Inclusion of incorrect component
6. Incorrect job
7. Operation error
8. Tool or equipment error
9. Defects in job components
10. Measurement error
Consider Mistake Proofing against these having any impact on your Key Xs.
ERRORS
DEFECTS
DEFECTIVES
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 18
Human Errors That Lead To PotentialKey X Variation
1. Forgetfulness
2. Errors due to misunderstanding
3. Errors in identification
4. Errors made by untrained workers
5. Willful errors (ignore rules)
6. Inadvertent errors (distraction, fatigue)
7. Errors due to delay in decision making
8. Errors due to lack of standards
9. Surprise errors (malfunctions)
10. Intentional errors (sabotage)
Also consider Mistake Proofing against these having any impact
on your Key Xs.
ERRORS
DEFECTS
DEFECTIVES
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 19
Red Flag Condition
• What is a Red Flag condition?
• You will find that in some projects, after you have identified the Key Xs and their optimal settings, one or more of them may be extremely difficult to control. The control plan should attempt to provide robust control mechanisms, however it may be difficult to do so withoutMistake Proofing. Some examples:- Training was found to be critical, but the operation has 150% turnover- Cycle Times are very long, so the operators tend to lose concentration
and Key X breakdowns may not be observed even though gages/process measurements show the issue
Mistake Proofing is a good control application for conditions such as these.
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 20
Common Red Flag Conditions
• Frequent changes to a job
• Complex processes
• Lack of standards
• Lack of measurement systems
• Lack of training
• Long Cycle Times
• Infrequent jobs
• High output
• Environmental conditions
• Attitude (motivation)
If one of these conditions exists in your process, consider Mistake Proofing as a control for your KPIVs
e.g., Lack of Training – Establish a system where only trained operators get engraved name plaques which are placed in a clearly visible slot on the machine/work station:
Untrained operator No plaque
No plaque Management Awareness Management Awareness Action
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 21
Implementation Road Map For Mistake Proofing
Describe the defect or potential defect including the
rate
Identify where the defect is likely to occur
Analyze current tasks associated with the operation
Identify error conditions contributing to the defect
Apply Five Why analysis to the error conditions to determine
root causes
Identify (using a team approach) Mistake Proofing
strategies
Verify the efficiency of the Mistake Proofing actions
(Key X)
(Process Map)
(Process Map)
(FMEA)
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 22
Mistake Proofing Strategies
Detect defects before they move
to next step
Detect errors during processing
Prevent errors from occurring
Good Best
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 23
Optional Class Exercise
• Pick a project from your team. On a flip chart create a column of the ten common error types. Create one or more columns of defects
• Complete the matrix (next page), first identifying defects that can be caused by the errors, then brainstorm and capture Poka-Yokes for the error/defects
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 24
Optional Exercise Data Matrix
Errors
1. Processing errors2. Error in setting up job3. Processing omissions4. Assembly omissions5. Incorrect component6. Incorrect job7. Operation error8. Tool or equipment error9. Defects in job components10. Measurement error
Defect 1
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Defect 2
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Poka-Yokes
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 25
Key Learning Points
•
•
•
•
•
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 26
Objectives Review
The participant will be able to:
• Communicate the concept of Mistake Proofing as a control method
• Apply Poka-Yoke methods as a control on identified key Xs- Reduce and/or eliminate process errors from occurring- Reduce and/or eliminate process defects from occurring
• Explain “Red Flag” conditions
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 27
Trademarks And Service Marks
Trademarks of Six Sigma Academy:Breakthrough DesignBreakthrough Software DesignBreakthrough DiagnosisBreakthrough ExecutionBreakthrough Lean® Breakthrough Sigma LeanBreakthrough Six SigmaBreakthrough Strategy® Breakthrough Value Services®
FASTARTINTELLEQMETREQ
WE WEAVE EXCELLENCE INTO THE FABRIC OF BUSINESS
Six Sigma is a federally registered trademark of Motorola, Inc.SigmaFlow is a trademark of Compass Partners, Inc.MINITAB is a trademark of Minitab, Inc.VarTran is a trademark of Taylor Enterprises
Copyright © 2001- 2004Six Sigma Academy International LLCAll Rights Reserved
Mistake Proofing Pg 28
Six Sigma Academy
www.6-sigma.com
US Tel: (480) 515-9501
US Fax: (480) 515-9507
International Tel: +44-1403-783456
International Fax: +44-1403-218788
8876 E. Pinnacle Peak Road, Suite 100
Scottsdale, AZ 85255